The so-called "Solo Remix" - which comes complete with a few new features and Square's trademarked inflated price tag - is out now on the App Store. It costs £12.99 / $17.99 on iPhone, and £13.99 / $19.99 on iPad.

The game follows Neku, a spiky-haired teen who wakes up in Tokyo's Shibuya district with the power to read minds. He also receives a text message that tells him that he's been 'invited' to participate in a seven-day gauntlet against some otherworldly foes.

You'll need to beat up monsters, make some new pals, collect magical badges, and wander the streets of Shibuya to survive this week-long battle. Oh, and figure out who is behind this twisted game.

Onward, to battle!

This iOS version sports a new combat system. On DS, two characters fought across two screens, with both buttons and touchscreen commands being used by the player. On Apple's gadgets, however, it's all done through taps and swipes, and multiple characters fight on the same screen.

You'll have to wait for our review to find out whether the touchscreen-friendly battle system is a suitable change.

Feature creep

Squeenix has taken the time to redraw a lot of the art and animation, to make it look snazzy on Retina display iPhones. The soundtrack includes some new songs and remixes, and there's even Twitter support, where you'll see tweets from your timeline when you read people's minds.

There's some multiplayer functionality thrown in, too. You can wirelessly exchange profiles with other players and they'll show up in your game, or you can play Tin Pin Slammer using the badges you find in the Story mode.

Are you compatible?

The World Ends with You has some steep technical requirements, and only the most recent devices are compatible with the game. On iPad, you'll need either an iPad 2 or the new iPad. On iPhone, you must have an iPhone 4 or a 4S.

iPod touch users, however, are completely left out of the party, as the game is incompatible with these devices. Sorry, guys, it's the end of the line.